Gun-barrel built of an a-tube and a breech-piece



J. VOLLMER.

GUN BARREL BUILT OF AN A-TUBE AND A BREECH PIECE.

- APPLlCATlON FILED 020.3. 1920.

1,398,819. g 4 7 2 1 atentedN0v.29,.1921.

6 a 2 SHEETS-$HEET 03% b Hg. 4 .12 v

J. VOLLMER.

N BARREL BUILT OF AN A-TUBE AND A BREECH PIECE.

A P P L l C A T l 0 N F l L E D D E C 3 I 9 2 0.

1,398,819. Patented Nov. 29,1921..

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G my DL/ l i lr/a/ 7 JOHN VOLLMER, OF ESSEN, GERMANY, ASSIGNOR TO FRIED.KRUPP AKT'IEN- V GES ELLSGHAFT, OF ESSEN-ON-TI-IE-RUHR, GERMANY.

GUN-BARREL BUILT OF AN A--TUBE AND A. BBEECH-IPIECE.

Specification of Letters Patent. Patented NQV, 29,

Application fi1ed December 3, 1920. Serial No. 428,086.

To all whom it may con cern Be it known that 1, JOHN VoLLMnn, residingat Essen, Germany, a citizen of the German Republic, have invented acertain new and useful Improvement in a Gun-Barrel Built of an A-tubeand a Breech-Piece, (for which I have filed application in Germany, May31, 1917,) of which the following 15 a specification.

This invention relates to gun-barrels built of an A-tube and abreech-piece, the latter being formed with a jacket portion whichenvelops the A-tube. vention is to provide such a connection between thesaid two parts of the gun-barre], as will combine suflicient resistanceto the stresses set up on firing with as low a weight as possible oftheconnecting parts, while effectually sealing the joint between thecomponent parts of the gun-barrel.

Referringto the annexed drawing Figure 1 is a longitudinal section ofthe parts in question of a constructional example of the invention;

Fig. 2 is a section at 2-2 in Fig. 1, seen from the right;

Fig. 3 is a longitudinal section of a Second constructional example ofthe invention;

Fig. 4 is a section at 44: in Fig. 3, seen from the right.

The gun-barrel shown in Figs. 1 and 2, which will be described first,consists of a double A-tube A A (Fig. 1) and a breechpiece B, the latterbeing formed with a jacket portion 6 which envelops the rear portion ofthe A-tube. The connection between the breech-piece and the A-tube isobtained by screwing the former on the latter. For this purpose, theouter layer A of the A-tube is provided with a screw thread 61 and thejacket portion 6 of the breech-piece is provided with correspondingfemale thread 5 denotes the slot to take the breech block, and b theloading aperture in the breech-piece B. The cylindrical wall 22 (Fig. 1)of the bore of the jacket portion Y b destined to receive the A-tube issloped off into the rear face of the said bore by an are b struck with acomparatively long radius, the said slope commencing at a point situatedin rear of the end face at a of the inner layer A of the A-tube. Thisend face a lies in one plane with the end face a of the outer layer A ofthe A-tube. Between The object of the in-I the faces a a and b thereremain two dishshaped empty spaces whlch open into the breech slot Thesespaces are filled up by 'means of two segment-shaped packing pieces "Cwhich are attached to the brcech-pieje B by fixing screws D.

Owing to the fact that the wall I) of the jacket portion 5 instead ofmaking a sharp or a slightly rounded angle with the face I) is slopedoff into the latter with an arc.

struck with a long radius, and that the A-tube retains its full diameterright up its rear faces a a great resistance of the breechpiece tocracking at the dangerous section where the wall I) merges intothe faceZ), and sufficient strength of the A-tube up-to its rear end to preventexpansion under the pressure of the powder gases, are obtained, togetherwith the least weight possible of the parts in question. The packingpieces C prevent dust and dirt penetrating into the joint between thelayers A A of the A-tube and into the screw joint a 6 between the A-tubeand the jacket portion of the breech-piece. against formation of rust atthe said joints and prevent the inner layer A, the so-called liner ofthe A-tube from setting back into the breech slot 6 and thus fromjamming the breech-block.

The second constructional example differs from the first only in thatthe packing pieces C fixed to the breech-piece B are dispensed with, therear end of the outer layer A of the A-tube A A being provided, instead,with extensions a of suitable shape. In order that a certain amount ofclearance may be provided for the screwing the breechpiece on the A-tubeand placing their connection under tension, the length of the extensionsa is determined in such a manner that they do not reach quite up to theface 6 (Fig. 3) of the breech-piece when the breech-piece assumes itscorrect position relative to the A-tube. The intervals E are closed,towards the breech slot 6 by covering strips F running parallel to thefront face of the breech slot. The said strips, which bear against therear face a of the liner A, engage undercut grooves (Fig. 3) of thebreech-piece, so that they cannot protrude into the breech slot. Endwisemotion of the strips F is prevented by fixing screws G. The strips Fprevent the en- Theyalso afford protection trance of dirt into theintervals E and effectually prevent the liner A from setting back intothe breech slot 6 In gun-barrels of the construction shown in Figs. 1and 2, similar strips can be employed, in case it should be considereddesirable to leave narrow gaps between the end faces a a of the A-tubeand the packing pieces 0. The height of the latter would then have to bereduced by an amount equal to the thickness of the strips.

Claims:

1. A composite gun barrel comprising a breech-piece provided with a boreand an A-tube adapted for screw threaded engagement therewith, the boreof said breechpiece terminating in an arc-shaped face curved on a largeradius, and packing pieces disposed in the arc-shaped face of said boreand adjacent the end of the A-tube.

2. A composite gun barrel comprising an A-tube and a breech-piece, saidbreech-piece being formed with a bore and provided with screw threadsfor receiving the end of the A-tube, the rear face of said bore beingareshaped with an arc struck on a large radius, said are shaped facecommencing at a point .to the rear of the adjacent end of the A-tube,

and packing pieces disposed between the areshaped face and the end ofthe A-tube.

3. A composite gun barrel comprising a breech-piece and an A-tubecomprising an outer member and a liner, said breech-piece being providedwith a bore for the reception of the A-tube, the cylindrical Wall ofsaid bore being sloped off into the rear face of the said bore by an arcstruck with alarge radius, the said slope commencing at a point in therear of the end face of the liner of the A-tube, and packing-pieces inthe rear portion of the bore of the breechpiece.

4. A composite gun barrel comprising a breech-piece and an A-tubecomprising an outer member and a liner, said breech-piece being providedwith a bore for the reception of the A-tube, the cylindrical wall ofsaid bore being sloped off into the rear face of the said bore by an arcstruck with a large radius, the said slope commencing at a point in therear of the end face of the liner of the A-tube and packing-pieces disposed between the rear face of the bore of the breech-piece and the endface of the A tube.

The foregoing specification signed at Essen, Germany, this 24th day ofJune, 1920.

, JOHN VOLLMER.

In presence of HANS GorTsMANN, JOHANN DECKERS,

